Gama, R. T.; de Oliveira, D. M.; Teixeira, W. G.; Falcão, N. P. S. Rev. Virtual Quim., 2017, 9 (5), 1944-1956. Data de publicação na Web: 4 de outubro de 2017 http://rvq.sbq.org.br Residual effect of biochar and saw dust powder on carbon and total nitrogen contents in Yellow Latosol in AmazoniaAbstract: The biochar (BC) acts as a physical, chemical and biological conditioner, which added to increasing doses of saw dust powder (PS) can contribute to soil improvement. The objective of this work was to verify the residual effect of BC and PS on total carbon, organic carbon, total nitrogen and carbon and nitrogen in a dystrophic yellow latosol in the central Amazon. The experiment was carried out at the experimental station of the National Research Institute of the Amazon, Manaus-AM. A randomized block design (4 blocks) was used in factorial tests, In the first plot (0, 40, 80, 120 t ha ). There was significant interaction at the 5% probability level between BC and PS in depth 10-20 cm, with the interaction of doses 80 BC and 40 PS presenting the best mean with 34.67 g kg -1 C. There was no significant effect for BC and PS on CO and soil organic matter (OM) in no depth. The residual effect of BC provided a significant increase at the level of 5% in total nitrogen contents at depths 0-10 and 10-20 cm. There was an increase in the C/N ratio due to the doses of BC in the three depths of the soil studied.Keywords: Soil organic matter; Yellow Latosol; Soil Conditioner. ResumoO biocarvão (BC) atua como condicionador físico, químico e biológico, que somado a doses crescentes de pó de serra (PS) podem contribuir para a melhoria do solo. Objetivou-se com este trabalho verificar o efeito residual do biocarvão e do pó de serra nos teores de carbono total, carbono orgânico, nitrogênio total e a relação carbono e nitrogênio em um Latossolo Amarelo Distrófico na Amazônia Central. O experimento foi realizado na Estação Experimental do Instituto Nacional de Pesquisas da Amazônia, em Manaus-AM. O delineamento utilizado foi o de blocos casualizados (4 blocos), em ensaio fatorial, na primeira parcela (0, 40, 80, 120 t ha -1 ) de BC, e na segunda foram aplicadas as doses de (0, 40, 80 e 120 t ha -1 ) de PS, totalizando 16 tratamentos e 4 repetições com 64 unidades experimentais. Foram determinados os teores totais de carbono total (CT) e nitrogênio (NT) pelo método de combustão a seco, carbono orgânico (CO) pelo método walkley & black e relação Carbono e Nitrogênio total (C/N). Houve efeito significativo no nível de 1% de significância nos teores de CT nas duas profundidades (0-10 e 20-30 cm) medida em que as doses BC aumentaram, sendo que houve uma diferença de mais de 80 % entre a dose 0 (17,86 g kg ). Houve interação significativa no nível de 5 % de probabilidade entre o BC e PS na profundidade 10-20 cm, sendo que a interação da dose 80 de BC e 40 PS apresentou a melhor media 34.67 g kg -1. Não houve efeito significativo para BC e PS nos teores de CO e matéria orgânica do solo (M.O) em nenhuma profundidade. O efeito residual do B...

Phosphorus is one of the most limiting elements in the amazon soil, requiring low cost alternatives that increase the agronomic efficiency of phosphate fertilizers for satisfactory crop production and biochar has been used as an option for increase soil fertility. The objective of this work was to evaluate the yield and properties of the biochar produced from the shell of Brazil nut fruit at 500 oC, as well as its behavior in the acidity and phosphorus availability from mineral source in Yellow Oxisol. The experimental design was completely randomized in a factorial arrangement (5 × 5) with five doses of biochar (0, 20, 40, 60 and 80 t ha-1) and five doses of P2O5 (0, 100, 200, 300 and 400 kg ha-1) in 20 kg pots. The trial was carried out at 365 days and the yield and properties of the produced biochar were evaluated, as well as the determination of acidity and total and available phosphorus. The biochar produced from feedstock was considered satisfactory, with 59%, which is a good alternative for producers. Aluminum contents were reduced confirming the potential of biochar as a corrective for acidity. Additionally, the amount of total and available phosphorus increased with increasing biochar doses. Thus, not only the feedstock but also the pyrolysis temperature showed hight potencial to improve the amount of phosphorus in the soil and decrease the soil acidity.

RESUMO A agricultura familiar está presente na maioria dos municípios do estado de Rondônia, o cultivo do pepino vem se destacando por participar cada vez mais da renda dos pequenos produtores, no entanto a falta de informações sobre o manejo adequado da cultura vem dificultando o aumento da produção. Portanto, objetivou-se com o presente trabalho avaliar o potencial produtivo do pepino (Cucumis sativus) submetido a dois sistemas de condução sendo um tutoramento horizontal e outro vertical, com e sem consórcio de amendoim (Arachis hypogaea). O experimento foi instalado no Campus experimental do curso de agronomia da Universidade Federal de Rondônia (UNIR), localizado no município de Rolim de Moura-RO. O delineamento experimental utilizado foi o em blocos casualizados, com quatro repetições e quatro tratamentos: 1-Tutoramento Vertical com Consórcio (TV-CC); 2-Tutoramento Horizontal com Consórcio (TH-CC); 3-Tutoramento vertical sem consorcio (TV-SC); 4-Tutoramento Horizontal sem Consórcio (TH-SC). As variáveis analisadas foram diâmetro, comprimento e peso do fruto e produtividade média. Observou-se que quando o pepino em consórcio com amendoim e conduzido com tutoramento horizontal (TH-CC) obtém uma elevada produtividade, evidenciando que esse sistema é vantajoso para as condições climáticas do estado de Rondônia.

The residual biomass of leaves and branches of fast returning species, such as bamboo, are the most promising for biochar production, and could be used as an excellent soil conditioner to recuperate degraded areas, stock carbon and recycling nutrients. The experiment was carried out on greenhouse condition as completely randomized design, under a factorial arrangement (3×3), been three pyrolysis condition (400 ºC, 500 ºC and 600 ºC), applied at 40 t ha-1 and three phosphate sources: Nature Phosphate (NP), Simple Superphosphate (SS) and Triple Superphosphate (TS) (100 kg ha-1 as P2O5), during one year with four crop rotation of cowpea and corn. The presence of biochar, independently of pyrolysis temperature, allowed value of shoot dry matter highest in the first two crops rotation and the P contents in the soil were increased up to third crop, however, it is showing statistic difference only in the soil after the two cowpea crops, in which the interaction showed similar behavior between the more soluble source (TS) and the less soluble source (NP). The concentrations of foliar P were similar between the two cowpea crops, thus in the corn crops the concentrations of foliar P were higher in the second crop and showed significance in the two crops. The presence of biochar modified the nature behavior of the phosphate sources, becoming similar P availability.

The objective of this work was to evaluate the degree of compatibility and agronomic performance in clonal genotypes of canephora coffee plants (Coffea canephora ex Froehner) for cultivation in the state of Rondônia, Brazil. The study was conducted with nine genotypes with three replications of Coffea canephora Arranged in the field: UFRO-60; UFRO-31; UFRO-61; UFRO-25; UFRO-03; UFRO-08; UFRO-21; UFRO-05 and UFRO-138 In adulthood and in two years of harvest (2013/2014 and 2014/2015). We evaluated: productivity, profitability, conversion index fruit cherry/grain benefited, mass of one hundred grains benefited, average diameter of the fruits, number of rosettes per branch, average distance between rosettes and number of fruits per rosette. Additionally, the degree of compatibility between the clones of clonal. The genotypes of Coffea canephora with the best agronomic performances evaluated for the edafoclimatic conditions of the State of Rondônia in this study were UFRO-08, UFRO-25, UFRO-03 and UFRO-138. According to the compatibility tests, the sequence of correct disposition in the field of Coffea canephora among the genotypes studied in this study are: UFRO-138; UFRO-31; UFRO-25; UFRO-08; UFRO-60; UFRO-21; UFRO-61; UFRO-03 and; UFRO-05. Close to 74% of the tests Were and self-pollination tests resulted in low fruiting, evidencing the characteristic of self-incompatibility.

Com as reservas de fósforo diminuindo gradativamente, o interesse em desenvolver alternativas para suprir a demanda de fertilizantes na agricultura vem sendo cada dia maior. Com isso, atentou-se para os resíduos orgânicos advindos do abate de animais, como ossos bovinos, que são fontes de fósforo (P) e cálcio (Ca) e podem ser destinados à agricultura. O único impasse na sua utilização é sua baixa solubilidade e disponibilidade de nutrientes às plantas. Assim, objetivou-se avaliar os efeitos produtivos da forrageira Brachiaria ruziziensis quando submetida à adubação com farinha de ossos calcinada (FOC) sob tratamentos ácidos (oxálico a 10 %, acético a 10 % e clorídrico a 1 e 0,5 %, respectivamente). Nas avaliações foram consideradas as seguintes variáveis: matéria fresca da parte aérea (MFPA), matéria seca da parte aérea (MSPA) e potencial hidrogeniônico (pH). Como padrão utilizou-se do superfosfato simples (SFS) para comparação. A acidificação da FOC proporcionou ganhos significativos de MFPA e MSPA na presença HCl 1% e o Acé 10% como extratores de P em relação à testemunha e à FOC sem utilização dos ácidos. A utilização de todos os ácidos na FOC proporcionou aumentos significativos no pH do solo.

Os quintais agroflorestais na Amazônia constituem-se como meio de subsistência e geração de renda aos agricultores. Assim, o presente trabalho objetivou caracterizar um quintal agroflorestal na Amazônia Central através de levantamentos socioeconômicos, patrimoniais e florísticos. O quintal agroflorestal foi dividido em cinco zonas quanto ao aproveitamento da área (Zona 0, 1, 2, 3, 4 e 5). Os proprietários possuíam baixa escolaridade, sem título final da terra e a maior parte da renda advém de aposentadoria. Dentre as espécies vegetais cultivadas no quintal estão o cupuaçu (Theobroma grandiflorum), o açaí (Euterpe oleracea), a mandioca (Manihot esculenta), o mari (Poraqueiba sericea) e a pimenta-do-reino (Piper nigrum). Os cultivos são manejados com baixa tecnologia, sem insumos externos, que favorece a conservação do meio ambiente.

One of the most relevant factors for the formation of coffee crops is to use quality seedlings. However, the competition of weeds for nutrients and water from the soil can negatively affect your obtaining. Thus, the control of weeds in nursery is often dependent on the use of herbicides, considering that the manual activity is costly. In this way, this work aimed to evaluate the effectiveness of weed control and the effects on the development of clonal seedlings of coffee (Coffea canephora Pierre ex Froehner) by application of herbicides oxyfluorfen and pendimenthalin in nursery conditions. The experiment was conducted under a completely randomized design in factorial scheme 2 × 5, two herbicides: Pendimethalin and Oxifluorfen in five doses: corresponding to 0, 1, 2, 4, 8 L.ha-1 of commercial products. Was evaluated during the experiment the emergence of weeds and to end (140 days), were evaluated: seedling Height, stem diameter, leaf area, number of sheets, number of roots, root length, root volume, dry mass of roots and shoot dry matter. There was significant effect for seedling height, shoot dry matter and total dry mass, in which the pendimethalin caused damage to seedlings in comparison to oxyfluorfen. The use of the herbicides Pendimethalin and Oxyfluorfen obtained satisfactory control of weeds with application of 1080g and 648 g a.i. ha-1, respectively.